I am currently borrowing the Lüderitzbuchter Zeitung 1909-1914, and I have scanned the Schiffsnachrichten in the late issues of 1910 without finding Primus. These shipping news concern passenger ships and they provide passenger lists. If Primus was another kind of vessel, it would probably not appear here.
Do you know anything more about the ship or the people on board? I have collected some records of people with connection to Lüderitzbucht at that time, see http://heim.ifi.uio.no/~jensj/Slekt/http://heim.ifi.uio.no/~jensj/Slekt/